Level 2: Mid-level evidence

Oral antibiotics appear as effective as IV antibiotics for treating severe UTIs, based on a systematic Cochrane review of 15 randomized trials comparing different modes of administration in 1,743 patients (children and adults) (Cochrane Database Syst Rev. 2007[4]:CD003237). Nine of the trials were in children, including six in children younger than 1 year. The review was limited by heterogeneity; in addition, most trials were small and there were few outcomes appropriate for meta-analysis.

Most comparisons found no significant differences in outcome: switch therapy (IV/IM followed by oral) vs. IV (six trials with 373 patients), oral vs. switch therapy (five trials with 1,040 patients), switch therapy vs. single-dose IV plus oral treatment (two trials with 225 patients), and single-dose IV plus oral treatment vs. oral treatment alone (one trial with 69 patients). In one small trial with 38 patients, IV treatment was associated with a higher rate of bacteriologic cure at the end of therapy compared with oral treatment.